<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package    CodeIgniter
 * @author    EllisLab Dev Team
 * @copyright    Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
 * @copyright    Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license    http://opensource.org/licenses/MIT    MIT License
 * @link    http://codeigniter.com
 * @since    Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Shopping Cart Class
 *
 * @package        CodeIgniter
 * @subpackage    Libraries
 * @category    Shopping Cart
 * @author        EllisLab Dev Team
 * @link        http://codeigniter.com/user_guide/libraries/cart.html
 * @deprecated    3.0.0    This class is too specific for CI.
 */
class CI_Cart {

    /**
     * These are the regular expression rules that we use to validate the product ID and product name
     * alpha-numeric, dashes, underscores, or periods
     *
     * @var string
     */
    public $product_id_rules = '\.a-z0-9_-';

    /**
     * These are the regular expression rules that we use to validate the product ID and product name
     * alpha-numeric, dashes, underscores, colons or periods
     *
     * @var string
     */
    public $product_name_rules = '\w \-\.\:';

    /**
     * only allow safe product names
     *
     * @var bool
     */
    public $product_name_safe = TRUE;

    // --------------------------------------------------------------------------

    /**
     * Reference to CodeIgniter instance
     *
     * @var object
     */
    protected $CI;

    /**
     * Contents of the cart
     *
     * @var array
     */
    protected $_cart_contents = array();

    /**
     * Shopping Class Constructor
     *
     * The constructor loads the Session class, used to store the shopping cart contents.
     *
     * @param    array
     * @return    void
     */
    public function __construct($params = array())
    {
        // Set the super object to a local variable for use later
        $this->CI =& get_instance();

        // Are any config settings being passed manually?  If so, set them
        $config = is_array($params) ? $params : array();

        // Load the Sessions class
        $this->CI->load->driver('session', $config);

        // Grab the shopping cart array from the session table
        $this->_cart_contents = $this->CI->session->userdata('cart_contents');
        if ($this->_cart_contents === NULL)
        {
            // No cart exists so we'll set some base values
            $this->_cart_contents = array('cart_total' => 0, 'total_items' => 0);
        }

        log_message('info', 'Cart Class Initialized');
    }

    // --------------------------------------------------------------------

    /**
     * Insert items into the cart and save it to the session table
     *
     * @param    array
     * @return    bool
     */
    public function insert($items = array())
    {
        // Was any cart data passed? No? Bah...
        if ( ! is_array($items) OR count($items) === 0)
        {
            log_message('error', 'The insert method must be passed an array containing data.');
            return FALSE;
        }

        // You can either insert a single product using a one-dimensional array,
        // or multiple products using a multi-dimensional one. The way we
        // determine the array type is by looking for a required array key named "id"
        // at the top level. If it's not found, we will assume it's a multi-dimensional array.

        $save_cart = FALSE;
        if (isset($items['id']))
        {
            if (($rowid = $this->_insert($items)))
            {
                $save_cart = TRUE;
            }
        }
        else
        {
            foreach ($items as $val)
            {
                if (is_array($val) && isset($val['id']))
                {
                    if ($this->_insert($val))
                    {
                        $save_cart = TRUE;
                    }
                }
            }
        }

        // Save the cart data if the insert was successful
        if ($save_cart === TRUE)
        {
            $this->_save_cart();
            return isset($rowid) ? $rowid : TRUE;
        }

        return FALSE;
    }

    // --------------------------------------------------------------------

    /**
     * Insert
     *
     * @param    array
     * @return    bool
     */
    protected function _insert($items = array())
    {
        // Was any cart data passed? No? Bah...
        if ( ! is_array($items) OR count($items) === 0)
        {
            log_message('error', 'The insert method must be passed an array containing data.');
            return FALSE;
        }

        // --------------------------------------------------------------------

        // Does the $items array contain an id, quantity, price, and name?  These are required
        if ( ! isset($items['id'], $items['qty'], $items['price'], $items['name']))
        {
            log_message('error', 'The cart array must contain a product ID, quantity, price, and name.');
            return FALSE;
        }

        // --------------------------------------------------------------------

        // Prep the quantity. It can only be a number.  Duh... also trim any leading zeros
        $items['qty'] = (float) $items['qty'];

        // If the quantity is zero or blank there's nothing for us to do
        if ($items['qty'] == 0)
        {
            return FALSE;
        }

        // --------------------------------------------------------------------

        // Validate the product ID. It can only be alpha-numeric, dashes, underscores or periods
        // Not totally sure we should impose this rule, but it seems prudent to standardize IDs.
        // Note: These can be user-specified by setting the $this->product_id_rules variable.
        if ( ! preg_match('/^['.$this->product_id_rules.']+$/i', $items['id']))
        {
            log_message('error', 'Invalid product ID.  The product ID can only contain alpha-numeric characters, dashes, and underscores');
            return FALSE;
        }

        // --------------------------------------------------------------------

        // Validate the product name. It can only be alpha-numeric, dashes, underscores, colons or periods.
        // Note: These can be user-specified by setting the $this->product_name_rules variable.
        if ($this->product_name_safe && ! preg_match('/^['.$this->product_name_rules.']+$/i'.(UTF8_ENABLED ? 'u' : ''), $items['name']))
        {
            log_message('error', 'An invalid name was submitted as the product name: '.$items['name'].' The name can only contain alpha-numeric characters, dashes, underscores, colons, and spaces');
            return FALSE;
        }

        // --------------------------------------------------------------------

        // Prep the price. Remove leading zeros and anything that isn't a number or decimal point.
        $items['price'] = (float) $items['price'];

        // We now need to create a unique identifier for the item being inserted into the cart.
        // Every time something is added to the cart it is stored in the master cart array.
        // Each row in the cart array, however, must have a unique index that identifies not only
        // a particular product, but makes it possible to store identical products with different options.
        // For example, what if someone buys two identical t-shirts (same product ID), but in
        // different sizes?  The product ID (and other attributes, like the name) will be identical for
        // both sizes because it's the same shirt. The only difference will be the size.
        // Internally, we need to treat identical submissions, but with different options, as a unique product.
        // Our solution is to convert the options array to a string and MD5 it along with the product ID.
        // This becomes the unique "row ID"
        if (isset($items['options']) && count($items['options']) > 0)
        {
            $rowid = md5($items['id'].serialize($items['options']));
        }
        else
        {
            // No options were submitted so we simply MD5 the product ID.
            // Technically, we don't need to MD5 the ID in this case, but it makes
            // sense to standardize the format of array indexes for both conditions
            $rowid = md5($items['id']);
        }

        // --------------------------------------------------------------------

        // Now that we have our unique "row ID", we'll add our cart items to the master array
        // grab quantity if it's already there and add it on
        $old_quantity = isset($this->_cart_contents[$rowid]['qty']) ? (int) $this->_cart_contents[$rowid]['qty'] : 0;

        // Re-create the entry, just to make sure our index contains only the data from this submission
        $items['rowid'] = $rowid;
        $items['qty'] += $old_quantity;
        $this->_cart_contents[$rowid] = $items;

        return $rowid;
    }

    // --------------------------------------------------------------------

    /**
     * Update the cart
     *
     * This function permits the quantity of a given item to be changed.
     * Typically it is called from the "view cart" page if a user makes
     * changes to the quantity before checkout. That array must contain the
     * product ID and quantity for each item.
     *
     * @param    array
     * @return    bool
     */
    public function update($items = array())
    {
        // Was any cart data passed?
        if ( ! is_array($items) OR count($items) === 0)
        {
            return FALSE;
        }

        // You can either update a single product using a one-dimensional array,
        // or multiple products using a multi-dimensional one.  The way we
        // determine the array type is by looking for a required array key named "rowid".
        // If it's not found we assume it's a multi-dimensional array
        $save_cart = FALSE;
        if (isset($items['rowid']))
        {
            if ($this->_update($items) === TRUE)
            {
                $save_cart = TRUE;
            }
        }
        else
        {
            foreach ($items as $val)
            {
                if (is_array($val) && isset($val['rowid']))
                {
                    if ($this->_update($val) === TRUE)
                    {
                        $save_cart = TRUE;
                    }
                }
            }
        }

        // Save the cart data if the insert was successful
        if ($save_cart === TRUE)
        {
            $this->_save_cart();
            return TRUE;
        }

        return FALSE;
    }

    // --------------------------------------------------------------------

    /**
     * Update the cart
     *
     * This function permits changing item properties.
     * Typically it is called from the "view cart" page if a user makes
     * changes to the quantity before checkout. That array must contain the
     * rowid and quantity for each item.
     *
     * @param    array
     * @return    bool
     */
    protected function _update($items = array())
    {
        // Without these array indexes there is nothing we can do
        if ( ! isset($items['rowid'], $this->_cart_contents[$items['rowid']]))
        {
            return FALSE;
        }

        // Prep the quantity
        if (isset($items['qty']))
        {
            $items['qty'] = (float) $items['qty'];
            // Is the quantity zero?  If so we will remove the item from the cart.
            // If the quantity is greater than zero we are updating
            if ($items['qty'] == 0)
            {
                unset($this->_cart_contents[$items['rowid']]);
                return TRUE;
            }
        }

        // find updatable keys
        $keys = array_intersect(array_keys($this->_cart_contents[$items['rowid']]), array_keys($items));
        // if a price was passed, make sure it contains valid data
        if (isset($items['price']))
        {
            $items['price'] = (float) $items['price'];
        }

        // product id & name shouldn't be changed
        foreach (array_diff($keys, array('id', 'name')) as $key)
        {
            $this->_cart_contents[$items['rowid']][$key] = $items[$key];
        }

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Save the cart array to the session DB
     *
     * @return    bool
     */
    protected function _save_cart()
    {
        // Let's add up the individual prices and set the cart sub-total
        $this->_cart_contents['total_items'] = $this->_cart_contents['cart_total'] = 0;
        foreach ($this->_cart_contents as $key => $val)
        {
            // We make sure the array contains the proper indexes
            if ( ! is_array($val) OR ! isset($val['price'], $val['qty']))
            {
                continue;
            }

            $this->_cart_contents['cart_total'] += ($val['price'] * $val['qty']);
            $this->_cart_contents['total_items'] += $val['qty'];
            $this->_cart_contents[$key]['subtotal'] = ($this->_cart_contents[$key]['price'] * $this->_cart_contents[$key]['qty']);
        }

        // Is our cart empty? If so we delete it from the session
        if (count($this->_cart_contents) <= 2)
        {
            $this->CI->session->unset_userdata('cart_contents');

            // Nothing more to do... coffee time!
            return FALSE;
        }

        // If we made it this far it means that our cart has data.
        // Let's pass it to the Session class so it can be stored
        $this->CI->session->set_userdata(array('cart_contents' => $this->_cart_contents));

        // Woot!
        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Cart Total
     *
     * @return    int
     */
    public function total()
    {
        return $this->_cart_contents['cart_total'];
    }

    // --------------------------------------------------------------------

    /**
     * Remove Item
     *
     * Removes an item from the cart
     *
     * @param    int
     * @return    bool
     */
     public function remove($rowid)
     {
        // unset & save
        unset($this->_cart_contents[$rowid]);
        $this->_save_cart();
        return TRUE;
     }

    // --------------------------------------------------------------------

    /**
     * Total Items
     *
     * Returns the total item count
     *
     * @return    int
     */
    public function total_items()
    {
        return $this->_cart_contents['total_items'];
    }

    // --------------------------------------------------------------------

    /**
     * Cart Contents
     *
     * Returns the entire cart array
     *
     * @param    bool
     * @return    array
     */
    public function contents($newest_first = FALSE)
    {
        // do we want the newest first?
        $cart = ($newest_first) ? array_reverse($this->_cart_contents) : $this->_cart_contents;

        // Remove these so they don't create a problem when showing the cart table
        unset($cart['total_items']);
        unset($cart['cart_total']);

        return $cart;
    }

    // --------------------------------------------------------------------

    /**
     * Get cart item
     *
     * Returns the details of a specific item in the cart
     *
     * @param    string    $row_id
     * @return    array
     */
    public function get_item($row_id)
    {
        return (in_array($row_id, array('total_items', 'cart_total'), TRUE) OR ! isset($this->_cart_contents[$row_id]))
            ? FALSE
            : $this->_cart_contents[$row_id];
    }

    // --------------------------------------------------------------------

    /**
     * Has options
     *
     * Returns TRUE if the rowid passed to this function correlates to an item
     * that has options associated with it.
     *
     * @param    string    $row_id = ''
     * @return    bool
     */
    public function has_options($row_id = '')
    {
        return (isset($this->_cart_contents[$row_id]['options']) && count($this->_cart_contents[$row_id]['options']) !== 0);
    }

    // --------------------------------------------------------------------

    /**
     * Product options
     *
     * Returns the an array of options, for a particular product row ID
     *
     * @param    string    $row_id = ''
     * @return    array
     */
    public function product_options($row_id = '')
    {
        return isset($this->_cart_contents[$row_id]['options']) ? $this->_cart_contents[$row_id]['options'] : array();
    }

    // --------------------------------------------------------------------

    /**
     * Format Number
     *
     * Returns the supplied number with commas and a decimal point.
     *
     * @param    float
     * @return    string
     */
    public function format_number($n = '')
    {
        return ($n === '') ? '' : number_format( (float) $n, 2, '.', ',');
    }

    // --------------------------------------------------------------------

    /**
     * Destroy the cart
     *
     * Empties the cart and kills the session
     *
     * @return    void
     */
    public function destroy()
    {
        $this->_cart_contents = array('cart_total' => 0, 'total_items' => 0);
        $this->CI->session->unset_userdata('cart_contents');
    }

}
